Y17DT: presiune turbo

verifica tot traseul de aer + EGR-ul. La mine a fost un furtun spart (cel in forma de L).

tocmai, traseul este altul. aerul din admisie are presiune mai mare si scapa direct in evacuare prin intermediul EGR-ului.

Salut

Poti fi mai precis sau poti pune o poza cu furtunul care l-ai inlocuit, ca aceiasi problema o am si eu cu lipsa de putere mai ales cand motorul este cald (y17dti).

Exemplu de calcul intre mg/stroke si kg/hour[in engleza] si alte informatii utile[cred] pt. cei mai putin cunoscatori.O sa revin cu scheme ,module de amplificare debitmetre uzate,nu distruse care sa le aduca tensiunea de iesire la valoarea unuia bun. At 900 RPM a 4 cilinder 4 stroke engine makes 900 RPM * 2 strokes/revolution * 60 minutes in one hour = 108,000 strokes. So if the ECU reads 480 mg/stroke at idle, it equals to 108,000 * 480e-6 = 52 kg/hour air flow. 480 mg/stroke is the value you should read with a 1.9L engine during idle when the EGR is closed. One full cilinder filling is 0.48 liter. Air is about 1290 mg per liter. So one could calculate 0.48 * 1290 = 619 mg/stroke. However, the cilinder is not fully filled as it has to suck in the air in a limited amount of time. Therefore the value is a little lower. (If the turbo would be really working at idle, the air flow could be higher than 619 mg/stroke.) The output voltage of a Pierburg MAF during idle and closed EGR is about 1.6V. A Bosch MAF reads about 2.2V in this situation. With a closed EGR you should measure about 480mg/stroke. With a 78% opened EGR you should read about 290 mg/stroke. If the values you find are much lower, something is blocking the air flow or the MAF has gone bad. The air flow can be blocked by a clogged air filter, a clogged intercooler, a (partly) closed anti shudder valve, a clogged intake manifold or bad valves. The intake manifold may clog due to soot/oil as exhaust fumes are fed back into the engine by the EGR and oil is fed into the engine by the CCV. It's also possible that the EGR is stuck open. Below is

Aveam pe undeva schema interna debitmetru bosch si senzoru de temperatura [termistorul] nu influenteaza ,ci doar citeste temperatura masei de aer si o trimite la ecu.Deci tensiunea de iesire maf ramane proportionala cu masa de aer doar ca e mai mica la unul uzat [pelicula cu depuneri ,invechire].Operationalul 741 ar lucra bine la alimentare dubla,se complica scema.Un ci bun este lm158,258,358 care functioneaza la tensiune mica si unica.

Din alt sait,in engleza- After measuring a very dead MAF which reported 600mg/stroke in stead of the required 850mg/stroke at 3000 RPM WOT on the bench, I realized that this MAF was 15% off from 0 to about 200 kg/hr. I couldn't get more than 200kg/hr airflow on the bench, so I just concluded that this 15% would be there for the full airflow range.

cu un circuit simplu cu un tranzistor BD139 cu baza la +5v printr-o rezistenta, feedback de pe colector in baza si rezistenta in emitor se poate face ajustarea tensiunii de iesire in anumite limite.

Sau o alta varianta ar fi ajustarea hartii de liniarizare MAF din ECU. Parca la Delco este o harta in functie de presiunea atmosferica si mV cu outputul in mg/stroke aer. Problema este ca orice ai face un debitmetru pe duca va continua sa isi schimbe valorile.

Se gasesc pe ebay cu mufe pt tipul de masina .Postez o schema de pe alt forum.

Nu am inteles rolul rezistentei R5 si RV1 care reglata la masa ar pune in scurt iesirea maf.Apoi alimentat la 12-14v montajul din varii motive ar putea depasi 5v la iesire periculos pt ecu.Se poate pune o dioda zener de protectie dar cel mai bine alimentat de la un stabilizator de 6-8v max.Uout =Ualim-1...2,5v in functie de operational.