Hi i understand i am new to this forum and i was wondering if anyone would be kind enough to help me with a problem that has been costing alot of money to solve the problem which has not done the job

1984 HiAce Engine Van

Description of problem:
The car seems to be running flat spots under load and up hill

Had vehivle Checked on Dyno results as shown

Faulted A/F Ratio very lean at cruise no load and underload checked.
Fuel Pressure OK 3.5PSI at Idel and Underload.
Timing on dyno Ok.
Operation of Advance Unit ok
Found that A/F Ratio 15.6-1 Light Cruise and can go up to 17.5-1 unlderload.

Parts replaced to try and fix problem are as follows:
Spark Plugs
Fuel Pump
Distributor Points and leads
Fuel Filter 3 times
Two Carbys replaced and checked by expert

Description of problem is when idle Van seems to run smooth but when underload and going up hill power is lost significantly and seems to be pulling back i have also had an engine pressure test done which came up ok

If anyone knows what else might be the cause let me know the latest that i have heard is that secondry valve on carby might not be opening.

Please email me at ital2play@hotmail.com

Thanks (IMG:style_emoticons/default/liebe011.gif)

Hi
new too long shot but the gearbox could be holding the engine back causing it to die
Brendan 78

what makes u think it could be the gearbox any other suggestions any help would be appriciated

thanks (IMG:style_emoticons/default/gunsmilie.gif)

I believe the gearbox suggestion refers to the added friction it could be causing thus slowing the van down uphill etc where it would be more noticable than on flat ground... I guess the diff could be doing similar? not sure it explains the A/F ratio's though....

have you checked for an intake manifold gasket leak? could be a small hole there causing more air (than needed) to be sucked in when under load.... also the associated hoses etc check for splits, perishing etc

might also be worth getting the value clearances checked....

what motor is it? my '82 hiace camper had an 18r and I ditched the factory carby and installed a weber 32/36 tiwn barrel downdraft from memory.... noticable improvement all round!! could be a way of ruling out the carb depending on what motor you're running....

Before you go spending money or doing very big jobs like gerabox or big carbs, check the basics first.

You say you have done a compression test which as come up Ok, so next, do everything to check the spark is doing what it should, then, check the fuel supply

Check the points, or replace them if you know they are more than 30,000kms old. Check ignition timing, check distributor cover and leads etc. These are all service items which wear out over time, if the van has been neglected for a few years then these need replaced. You say you've done the spark plugs, but new leads wont harm as well.

Then check the fuel, is there enough clean fuel and clean air getting to the carb? if not maybe the fuel filter is clogged or the line from the tank is collapsing on its inside. Replace both if you are unsure. Check fuel pump, and air filter, and last of all check the carb itself.

None of the above is rocket science, ask a knowledgeable mate to help and get a decent workshop manual.

You can google "engine fades under load" or similar descriptions of the symptoms, see what comes up. In the old days a haynes manual used to have a "trouble shooting" or "fault diagnosis" section, and "engine fades under load" is a common fault which is easily and cheaply rectified.